The present invention reltes to a data processing system and more particularly to a system for accessing serially-stored memories, especially charge-coupled memories. Charge-coupled devices (CCD) have been investigated for use in semiconductor memories, particularly those employed metal-oxide-silicon (MOS) technology in order to lower the cost of such memories as compared to dynamic random-access memories (RAM), magnetic disc and tape memories which are in present use. Present CCD memory technology has fabricated CCD memories having four times the density per package at 1/4 the cost per bit of a dynamic RAM memory. One disadvantage of CCD memories systems is their slower access time as compared to random-access memories employing MOS technology. It is therefore an object of the present invention to provide a serial memory system in which access time to the serial memory approaches those presently obtained with random-access memory systems. It is a further object of this invention to provide a CCD memory system which is relatively simple in structure and therefore low in cost.